Add health check URL

[gene1wood]

If we can do this with openresty / LUA

Let's add a path (e.g. /health ) that when hit

• Hits the backend service at a fixed path (e.g. /)
• Checks if it gets back a 200
• If it does, it serves back a 200 OK health check page and if not it serves a non-200 HTTP response code

This allows for load balancers to know when a mozilla.oidc.accessproxy fronted service is actually ready to accept traffic.

One risk we need to think about is if there's any potential for using the timing of the response of the health check page to divine differences in the backend service page that's being checked.

[gdestuynder]

i think you put it in right?

[gene1wood]

What we have currently is this.

Problem is, it doesn't care what the backend state is in and will happily tell a load balancer to send it taffic when the backend is serving 500s

So the change would be to have this endpoint hit an unauthenticated endpoint on the backend service and report back the status code as the status code of the /health page (or something like that.